As computing devices offer increasing processing capacity and functionality, users are able to operate these devices in an expanding variety of ways. For example, users can utilize audio recording and playback devices to record then playback the recorded audio signal using an application that transforms or modifies the recorded audio. Conventionally, these applications transform the audio by applying one or more filters or other modifications to the input audio signal, where each filter can adjust a playback speed, volume level, or add a sound effect (e.g., morph or change a voice) to the input audio signal, among others. These approaches often sound computer-generated, or are otherwise limited in their ability to replicate speech or other audio input in a way that sounds to a user as if the modified speech was originally produced or recorded by a character or other such entity.